Next step in diagnostics?

[Mick D]

Hi

MCR2 manual available here:

https://archives.jampot.dk/technical/El ... x_MCR2.pdf

Regards Mick

[mattlacey]

Well I had some time Sunday morning, so I opened it up and cleaned the contacts. Couldn't see anything obvious, the normally closed side was closed and would open when I rocked the top, the open side was open and closed when I did the same. Couldn't find any breaks in continuity around it either so nothing obvious, though when I fired the bike up there was no sign of life from it.

Next up I pulled the lgiht switch and ammeter off the front, and everything there looked good. Seemed to have continuity in all the right places from the front to the back of the loom, though it's a bit of a crap shoot with wire colours! Then I took it out for a ride, and noticed that the Ammeter was generally below 0, but when the revs climbed it suddenly start to oscillate pretty wildly between +ve and -ve by quite a distance. I'm guessing that means the regulator is doing something at that point and maybe I wasn't revving it enough when I tested at stand still with the cover off.

Could the battery being low affect the functioning of the regulator? The lights etc. did work when I got the bike so it was clearly putting out more than it's current 3.3V at some point, and I'm guessing it's just never charged off the dynamo since I've had it. I might order a solid state replacement for now to use as a diagnostic tool as much as anything - at least I could then eliminate (or not) the regulator as a problem, and at worst I'd have a backup unit to keep in the toolbox!

[MarkO]

Have you cleaned up the dynamo commutator/brushes? A cotton bud soaked in carb. cleaner does a good job. Old regulators are fairly numb things and certainly the newer units at least do not charge if the battery is weak. May be similar for your old box of coils. Personally I'd change it out - for piece of mind if nothing else.

[will_curry]

For the system to charge both the dynamo and the control box need to be working properly and correctly
connected. Have you worked through John Nash's excellent diagnostics at viewtopic.php?t=189

Foe what it's worth I've gone back to using the original setups after trying various electronic regulators on my singles.

[mattlacey]

Yeah I found that guide - I need to get hold of a moving needle meter, but the dynamo does seem to be putting power out. I did wonder if it's because the battery is low that it's not charging, but my charger doesn't do 6v which is annoying.

[MarkO]

Stick another 6V battery in series and charge it that way? It may indeed not be charging as the battery is too weak for the regulator, but that will need verifying from someone who knows better than me. A new 6V battery cannot be that much from Tanya or somewhere?

[will_curry]

If the dynamo and control box - MCR2 - are working as intended they will happily work without a battery.

I ran one of my singles for years without a battery with just the dynamo and control box powering the lights.
Even now, with the battery completely flat it will charge the battery.

[MarkO]

Will - interesting. If you ran without a battery, did your lights not die when stationary?

[will_curry]

As long as the engine was running I had lights.

[JohnnyBeckett]

h, i run my matchless 500 twin for years without a battery and had good lights when running like Will says and it had sidecar box with a light on top of the mudguard on the 3 wheel